The English abbreviation and its explanation involved in the present text are as follows.    3G: the 3rd-Generation mobile communication technology;    LTE: the Long Term Evolution system;    GSM: the Global System of Mobile Communication;    EPC: the Evolved Packet Core;    eNB, eNodeb: the Evolved Node B;    E-URTAN: the Evolved Universal Terrestrial Radio Access Network;    UE: the User Equipment (the user terminal);    MME: the Mobility Management Entity, which is a core network element related to mainly processing the signaling;    S GW: the Serving Gateway, which is a core network element related to mainly processing the service;    Femto: the Femtocell system, mainly including the Femtocell and the Femto gateway;    HNB: the Home Node B, the Femtocell using the 3G mode;    HeNB: the Home eNB, the Femtocell using the LTE mode;    HeNB GW: the Home eNB Gateway (HeNB gateway);    SCTP: the Stream Control Transmission Protocol;    TAC: the Tracking Area Code;    CSG: the Closed Subscriber Group;    PLMN: the Public Land Mobile Network;    HeMS: the Home eNB management system;    Global eNB ID, the global network eNB identifier;    AP: the Access Point.
The LTE system is the evolution of the 3rd generation mobile communication system, and the whole LTE system is made up of three parts, the eNB, the EPC and the UE. FIG. 1 shows a network structure chart of a LTE system. The eNB is an evolved base station, the EPC is responsible for the part of the core network including the MME and the S GW, and the UE is the user terminal, wherein, multiple eNBs at the E-URTAN side access the MME/S GW through the S1 interface, and every eNB is connected to another eNB through the X2 interface.
With the continuous extension of the scale of the macro network (the 3G network or the LTE network), the user quantity is increasing constantly, and the data bandwidth requirement of the user is increased constantly. Because the utilization frequency of the 3G network and the LTE network is higher, and its penetrability of the signal is poor when compared with the GSM, the indoor coverage becomes a difficult point of the network optimization, and the indoor coverage of the 3G network or the LTE network is generally realized by adopting the mode of establishing the indoor allocation system. However, under the existing condition, the indoor allocation system can generally be established only in some hotels, medium-to-high grade communities or public hotspot places. As to the general residential quarters, limited to various conditions, it is unable to establish the indoor allocation system, so the indoor 3G or LTE signal is very weak or even there is no signal at all, which causes great influence to experience the user experience.
For this reason, a Femto system, that is the Femtocell system, has already been proposed. Its adopted public broadband or operator transmission access is accessed to the security gateway and the core network of the operator through the Internet, thus providing the wireless signal coverage to the user, which can improve the user experience and is an important technology to fill the blind area and fill the hot point of the indoor coverage. About the Femto system, it is mainly made up of the Femto base station and the femto gateway, wherein, the Femto base station is divided into the Femto base station using the 3G mode and the Femto base station HeNB using the LTE mode according to the difference of its adopted wireless technologies.
FIG. 2 shows a network element structure diagram of a Femto system of the LTE mode. The HeNB GW is introduced into the LTE system, and multiple HeNBs are linked with the HeNB GW. First of all, the HeNB GW is one-to-multiple connected to multiple HeNB through the S1 link; secondly, the HeNB GW further one-to-multiple accesses multiple MME/S GWs through the S1 link to perform load sharing and disaster recovery backup. In addition, the HeNB can also access the MME/S GW through the S1 directly. In the Femto system framework of the LTE mode in FIG. 2, it can be seen from the connection relation of every network element, as to the MME, the HeNB GW is equivalent to the macro station eNodeb; as to the HeNB, the HeNB GW is equivalent to the MME, so no matter the HeNB is linked with the MME/S GW directly, or the HeNB is linked with the MME/S GW through the HeNB GW, the definition and function of the S1 interface during that time are totally consistent. Other network elements of the Femto system of the LTE mode further include the HeMS (not shown in FIG. 2), used for configuring the related parameter of the HeNB.
As to the macro network base station eNB, the current protocol stipulates that there is and can only be one SCTP link between one MME and one eNB, which has no problem for the macro network eNB because the number of the users under one macro-base station is limited and one SCTP can already meet the requirement of the upper layer service. But after introducing the HeNB GW, tens of thousands of or even hundreds of thousands HeNBs are linked under one HeNB GW, the number of the users is increased sharply; the networking requirement is far from being satisfied if still according to the protocol; it is very difficult to meet the requirement of the vast capacity of users if only one SCTP link is established between one HeNB GW and one MME, once the number of the users increases to a certain extent, a large number of signaling loss or data packet loss is inevitable, and the gateway stability is unable to be guaranteed.